Aerial photo taken on Oct. 13, 2016 shows the Dalong Reservoir in south China's Hainan Province. Hainan is the southernmost province of China and is also the province with the smallest land area and the largest ocean area. The resort island of Hainan boasts fresh air, clean rivers and high forest coverage rate. Sansha city in Hainan was established in 2012. Since then, the city government has intensified measures to improve the environment of the islands in Sansha. More than 3 million seedlings have been planted in Sansha, with the forestation rate passing 90 percent in some islands. Benefiting from its natural environment, Hainan is famous for its fairly good air quality. In 2018, the share of good air quality days in Hainan reaches 98.4 percent. From 21 to 23 in July, the "Hainan Day" event was held at the ongoing Beijing International Horticultural Exhibition, where visitors can experience the beauty of tropical island landscape of Hainan. (Xinhua/Yang Guanyu)